The present invention relates to an ink jet recording apparatus comprising a recording section at which a recording head is reciprocated in a main scanning direction while ejecting ink therefrom to execute recording over a fed recording paper, and a transporter for intermittently transporting the recording paper in a subscanning direction, and a paper discharger provided in the ink jet recording apparatus.
In such an ink jet recording apparatus, a phenomenon which is generally referred to as a so-called cockling phenomenon is generated by the water content of ink discharged onto the recording surface of the recording sheet so that the recording paper is corrugated in the main scanning direction. Although the corrugation of the recording paper which is generated by the cockling phenomenon has already been regulated to have a wave in a small cycle of approximately 10 mm to 25 mm, thereby preventing a great corrugation (for example, disclosed in Japanese Patent Publication No. 2000-71532A), there has not been found an ink jet recording apparatus which is able to reduce the corrugation itself.
Moreover, since a recording paper referred to as a so-called plain paper does not have a high rigidity differently from a special sheet preferably used for performing photograph-like recording which realizes advanced picture quality, there is generated a phenomenon in which the recording paper is curled through the step of once moistening the recording surface of the recording paper by the water content of the ink discharged onto the same recording surface and then drying the same recording surface. The curl becomes more remarkable if the amount of the ink discharged onto one recording paper is larger, that is, an ink duty is increased.
In a state where the ink landed onto the recording paper is dried, both sides are curled to surround the recording surface inwardly in most cases. The degree of the curl is varied depending on the firmness of the paper, that is, the rigidity or the ink duty in printing. In some cases in which the degree of the curl is the greatest, the recording paper is curled cylindrically.
Therefore, in the case where the recording paper obtained after the execution of the recording has the corrugation caused by the cockling phenomenon, conventionally, the corrugation is manually corrected to be reduced, for example, the recording paper is interposed between flat plates to apply a load, or the corrugation is left as it is.
In the case where the recording paper is curled cylindrically, a user is obliged to correct the curl. In addition, in the case where the user corrects the recording paper curled cylindrically, the recording paper is forcibly curled manually in a reverse direction to the direction of the curl. Consequently, an irregular wrinkle or a locally small curved portion is newly generated. Even if the curl can be mended to some degree, the uniform flatness of the whole recording paper cannot be obtained, that is, the recording paper itself is damaged. Thus, there is a problem in that the quality of a printed matter is deteriorated.